I was having that problem by using a js from a static resource. I called the script like this:

<ltng:require scripts="{'resource/AdapterSR/adapter-master/src/js/adapter_core.js'}"
                  afterScriptsLoaded="{!c.doInit}"/>

I dont know what is happening. If its because of the lockerservice or what. 

Hi, i was trying to use the WebRTC API by calling the method navigator.MediaDevices.getUserMedia() in my lighning component, but i get errors.

Is it possible to use the API in a lightning component?